We will investigate the role of Vitamin E in preventing or modifying the course of bronchopulmonary dysplasia in low birthweight infants requiring oxygen and assisted ventilation during treatment of the respiratory distress syndrome. Human and animal studies will be carried out. In human studies, Vitamin E influences will be assessed using clinical and radiographic criteria. We will also determine influences of Vitamin E on incidence of retrolental fibroplasia and on red cell hydrogen peroxide stability and lipid peroxide formation in infants receiving oxygen therapy. Effects of Vitamin E on surfactant production will be determined by examining phospholipids in trachial aspirates of infants intubated for ventilatory support. We will also examine the protective influence of Vitamin E in oxidant stressed newborn rabbits. These studies will utilize normal and Vitamin E deprived animals. Studies to be carried out include measurement of lipid peroxide formation in lung and red cells in controls and different Vitamin E groups, determination of phospholipid synthesis using lung slice and lavage techniques, determination of influences on oxidative metabolism and on glutathione reductase and peroxidase activities. Pathological correlations will be carried out at the light and electron microscopic levels. These studies will hopefully permit us to confirm preliminary evidence suggesting a protective effect of Vitamin E in preventing severe bronchopulmonary dysplasia and should also provide new information concerning oxygen toxicity and effects of Vitamin E on lung function and metabolism in the newborn.